Nanocrystalline TiO₂(B) as Anode Material for Sodium-Ion Batteries

Abstract

<p>High surface area, nanostructured, and phase-pure TiO2(B) noodles-like secondary particles were successfully synthesized by a<br /> facile one-pot synthesis, based on the hydrolysis of TiCl3 using a mixture of ethylene glycol and water at moderate temperature. The<br /> primary nanoparticles have a uniform size and are about 15 nm in diameter as determined by TEM analysis and exhibit an increased<br /> exposure of the (010) facet as indicated by XRD analysis. Unlike the electrochemical reaction with lithium, the application as sodiumion<br /> electrode material reveals substantial differences, including the initial amorphization of the TiO2(B) particles, accompanied by<br /> a partial irreversibility of the sodium storage, presumably related to sodium trapping inside the active material particles and the<br /> absence of a stable solid electrolyte interphase, as indicated by galvanostatic cycling and electrochemical impedance spectroscopy,<br /> respectively. Besides, TiO2(B)-based electrodes show a stabilized reversible capacity of about 100 mAh g−1 and a very good C rate<br /> capability.</p>